During wash and rinse cycles, dishwasher appliances generally circulate a fluid through a wash chamber over articles, such as pots, pans, silverware, etc. The fluid can be, e.g., various combinations of water and detergent during the wash cycle or water (which may include additives) during the rinse cycle. Typically, the fluid is circulated during a given cycle using a pump. Fluid is collected at or near the bottom of the wash chamber and pumped back into the wash chamber through, e.g., nozzles in spray arms and other openings that direct the fluid against the articles to be cleaned or rinsed.
Depending upon the level of soil on the articles, fluids used during wash and rinse cycles will become contaminated with soils in the form of debris or particles that are carried with the fluid. In order to protect the pump and recirculate the fluid through the wash chamber, it is beneficial to filter the fluid so that relatively clean fluid is applied to the articles in the wash chamber and materials are removed or reduced from the fluid supplied to the pump.
Accordingly, dishwasher appliances are generally provided with a filter assembly to trap at least certain of the soils carried with the wash fluid. Such filter assemblies are generally fluidly connected with the pump, such that the fluid circulated by the pump is relatively clean. In certain dishwasher appliances, the pump pressurizes the filtered fluid and provides the pressurized fluid through various conduits to the spray arms position within the dishwasher appliance. At the end of a wash cycle, however, the pump stops providing pressurized fluid through various conduits. At such time, the weight of the fluid positioned in the conduits may cause a reversal of the flow through the pump. Such a reversal in the flow of fluid through the pump can also be directed back through the filter assembly, carrying soils previously trapped during operation back into the wash chamber of the dishwasher appliance.
Accordingly, a dishwasher appliance capable of preventing previously trapped soils from traveling back into the wash chamber would be beneficial. More particularly, a filter assembly capable of deterring a reverse flow of fluid through the filter assembly would be particularly useful.